Most existing forms of exercise apparatus are too large or heavy to be easily transported or stowed. Examples include weight lifting equipment, rowing machines, and exercise cycles. Some portable strength-building equipment is available, such as elastic cords, but there is little portable equipment available that allows convenient indoor aerobic exercise.
It is advantageous to monitor and record the performance of the user during exercises. This is commonplace in gym equipment where performance monitors are fitted to most forms of aerobic exercise apparatus. Such a facility is uncommon in low cost portable exercise equipment.